Nanostructure Of Dragonfly Wings Kills Bacteria By Tearing Them To Pieces

With hundreds of millions of years of trial and error under its belt, nature has been a great inspiration for many technologies.Now, nature might also be able to provide us with a solution to one of the biggest problems facing medicine: the ability to killbacteria.

The wings of dragonflies have an incredible antibacterial property, and by harnessing this ability researchers hope they may be able to make antibacterial surfaces. A new study,published inApplied Materials & Interfaces, may have uncovered the secret of how dragonflies achieve this impressive feat, whichcould be of benefit ina range of situations, from hospitals to space exploration.

Looking at the intricate surface structure on the wings of dragonflies, the researchersnoticed something unusual. It had long been thought that the wings were able to kill the bacteria due to the fine nano-textured surface that resembles a bed of spikes, which physically puncture the cell walls of the bacteria and thus killit. However, a closer look revealed that these spikes were not ofuniform length as would be expected, but of varying heights.

The nanostructure of a dragonfly wing. Bandara et al. 2017

Further examination of the bacteria interacting with the surface also found another significant discovery. The cell walls of the bacteria never actually come into physical contact with the surface. Instead, the bacteria release structural molecules that act as a glue, sticking the microorganisms to the wing. So how, then, do the wings manage their impressive antimicrobial feat?

It turns out that the clue is in the varying heights of the spikes on the nano-textured surface. The bacteria dont die as soon as they land on the wings; in fact, they couldactually survive if they stayed in one place. But as soon as they start to move, the spines hold tight to the bacterial glue and the shearing forces exerted on the microorganisms simply tear themapart, fatally spewing theircellular contents.

The experiments conducted for this study need further exploration, namely seeing if the same process occurs forall types of bacteria, not just the gram-negative ones tested, as well as seeing if spikes that are allthe same length have the same effect.

The findingcould help lead to the production of surfaces that kill bacteria on their own, without the need to coat them with antibacterial chemicals. This could be vital in aclinical setting, in which there is concern that the overuse of antibacterial drugs are leading to microorganisms developing resistance that could be fatal to patients. It may also be of use to those searching for life on other planets, as contamination by Earth bacteria is a very real concern.

Read more: